Lipid profile adjustments may contribute to warming acclimation and to heat impact mitigation by elevated [CO2] in Coffea spp

This work was supported by European Union, Program Horizon 2020, call H2020-SFS-2016-2, action RIA, and Portuguese national funds from Fundacao para a Ciencia e a Tecnologia (project PTDC/ASP-AGR/31257/2017; Funding from CNPq (fellowships to E. Campostrini, F.L. Partelli, and F.M. DaMatta) is also acknowledged.An unexpected heat resilience, and the mitigation of heat impacts by elevated [CO2] were recently reported in Coffea spp. Plants must maintain membrane fluidity and integrity to cope with temperature changes, which requires an adequate lipid dynamics. This work provides the lipid profile (galactolipids, GL; phospholipids, PL; sulfolipids, SL) of chloroplast membranes, and the expression of a set of genes related to lipid metabolism in Coffea arabica L. (cv. Icatu and IPR108) and C. canephora cv. Conilon CL153, under elevated [CO2] (380 or 700 μL L−1), heat (25/20, 31/25, 37/30 and 42/34 °C, day/night) and their interaction. Major membrane lipids alterations, different among genotypes, included: A) responsiveness of total fatty acids (TFAs) synthesis to [CO2] (except IPR108) and heat (except CL153); stronger remodeling (unsaturation degree) in the 700-plants from 37/30 °C to 42/34 °C, coordinated at transcriptional level with the down-regulation of fatty acid desaturase FAD3 gene (C. arabica) and up-regulation of lipoxygenase genes LOX5A (CL153 and Icatu) and LOX5B (Icatu) at the highest temperature; B) quantitative and qualitative modifications in GL (monogalactosyldiacylglycerol, MGDG; digalactosyldiacylglycerol, DGDG), PL (phosphatidylcholine, PC; phosphatidylglycerol, PG), and SL (sulfoquinovosyldiacylglycerol, SQDG) classes, prompted by heat, elevated [CO2], and, especially, the interaction, in CL153 and Icatu. Overall membrane enrichment with MGDG and DGDG as a result of heat and [CO2] interaction in these genotypes, but at the highest temperature only in Icatu the high [CO2] maintained greater contents and unsaturation values of these GLs than in the 380-plants. C) Among PL classes, PG seems to play an active role in heat acclimation of C. arabica genotypes, increasing in 700-plants at 42/34 °C. Globally, Icatu often showed changes closer to those of heat tolerant cv. CL153 than to cv. IPR108. Overall, lipid profile adjustments in chloroplast membranes, from TFAs bulk until FA unsaturation within each class, are expected to contribute to long-term acclimation to climate changes in coffee plant.publishersversionpublishe

Protective Response Mechanisms to Heat Stress in Interaction with High [CO2] Conditions in Coffea spp.

This work was supported by national funds from Fundacao para a Ciencia e a Tecnologia through the projects PTDC/AGRPRO/3386/2012, the research units UID/AGR/04129/2013 (LEAF) and UID/GEO/04035/2013 (GeoBioTcc), as well through the grant SFRH/BPD/47563/2008 (AT) co-financed through the POPH program subsidized by the European Social Fund. Brazilian funding from CAPES (grams PDSE: 000427/2014-04, W.P. Rodrigues; 0343/2014-05, MM; 12226/12-2, LM), CNPq and Fapemig (fellowships to FDM, FP, and EC) are also greatly acknowledged.Modeling studies have predicted that coffee crop will be endangered by future global warming, but recent reports highlighted that high [CO2] can mitigate heat impacts on coffee. This work aimed at identifying heat protective mechanisms promoted by CO2 in Coffea arabica (cv. Icatu and IPR108) and Coffea canephora cv. Conilon CL153. Plants were grown at 25/20 degrees C (day/night), under 380 or 700 mu L CO2 L-1, and then gradually submitted to 31/25, 37/30, and 42/34 degrees C. Relevant heat tolerance up to 37/30 degrees C for both [CO2] and all coffee genotypes was observed, likely supported by the maintenance or increase of the pools of several protective molecules (neoxanthin, lutein, carotenes, ohtocopherol, HSP70, raffinose), activities of antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), and the upregulated expression of some genes (ELIP, Chaperonin 20). However, at 42/34 degrees C a tolerance threshold was reached, mostly in the 380 -plants and Icatu. Adjustments in raffinose, lutein, beta-carotene, alpha-tocopherol and HSP70 pools, and the upregulated expression of genes related to protective (FLIPS, HSP70, Chape 20, and 60) and antioxidant (CAT, CuSOD2, APX Cyt, APX ChI) proteins were largely driven by temperature. However, enhanced [CO2] maintained higher activities of GR (Icatu) and CAT (Icatu and IPR108), kept (or even increased) the Cu,Zn-SOD, APX, and CAT activities, and promoted a greater upregulation of those enzyme genes, as well as those related to HSP70, ELIPs, Chaperonins in CL153, and Icatu. These changes likely favored the maintenance of reactive oxygen species (ROS) at controlled levels and contributed to mitigate of photosystem II photoinhibition at the highest temperature. Overall, our results highlighted the important role of enhanced [CO2] on the coffee crop acclimation and sustainability under predicted future global warming scenarios.publishersversionpublishe

Selection and Validation of Reference Genes for Accurate RT-qPCR Data Normalization in Coffea spp. under a Climate Changes Context of Interacting Elevated [CO2] and Temperature

World coffee production has faced increasing challenges associated with ongoing climatic changes. Several studies, which have been almost exclusively based on temperature increase, have predicted extensive reductions (higher than half by 2,050) of actual coffee cropped areas. However, recent studies showed that elevated [CO2] can strongly mitigate the negative impacts of heat stress at the physiological and biochemical levels in coffee leaves. In addition, it has also been shown that coffee genotypes can successfully cope with temperatures above what has been traditionally accepted. Altogether, this information suggests that the real impact of climate changes on coffee growth and production could be significantly lower than previously estimated.info:eu-repo/semantics/publishedVersio